Endless crawler tread cycle



April 10, 1&45. A. LAN-DY ENDLESS CRAWLER TREAD CYCLE 6 Sheets-Sheet l Filed Oct. 2, 1941 MN Z April 10, 1945. A. LANDY 2,373,316

ENDLESS CRAWLER TREAD CYCLE Filed Oct. 2, 1941 6 Sheets-Sheet 2 April 10, 1945. LANDY 2,373,31fi

ENDLESS CRAWLER TREAD CYCLE I Filed Oct. 2, 1941 6 Sheets-Sheet 5 April 10, 1945. A. LANDY ENDLESS CRAWLER TREAD CYCLE 6 Sheets-Sheet 4 Filed on. 2, 1941 6 Sheets-Sheet 5 A. LANDY ENDLES CRAWLER TREAD CYCLE Filed Oct. 2, 1941 April 10, 1945.-

April 10, 1945. A. LANDY ENDLESS CRAWLER 'TREAD CYCLE 6 Sheets-Sheet 6 Filed Oct. 2, 1941 Patented Apr. 10, 1945 UNITED :STATES PATENT OFFICE.

ENDLESS CRAWLER TREAD CYCLE Arney Landy, Deer River, Minn. Application October 2, 1941, Serial No. 413,280

21 Claims. (01. ISO-9.2)

This invention relates to a vehicle and particularly to a motor driven vehicle of the motorcycle type having endless tracks at each side thereof.

It is an object of this invention to provide a motor driven vehicle of the motorcycle type having a frame, a seat supported above said frame so that the operator may straddle said frame in occupying said seat, pairs of wheels at the front and rear of said vehicle, endless tracks running,

over said wheels at each side of said frame together with means for. steering said vehicle.

It is a further object of the invention to provide such a motor driven vehicle as set forth in the preceding paragraph in which the wheels of each of said pairs converge toward their upper ends, the planes of said treads thus converging toward their upper runs.

w it is also an object of the invention to provide a motor driven vehicle such as set forth in the- It is still further an object of the invention to provide a motor driven vehicle of the motorcycle type having a frame, endless treads at each side of said frame together with means for pressing down on said treads at the central portion thereof respectively to lessen the friction at the end portions of the respective tread to facilitate turning of said vehicle. I

It is another object of the invention to provide a motor driven vehicle of the type above mentioned having a frame and endless tracks at each side of said frame together with means for breaking or retarding the movement of the track at one end of said frame to cause turning of said vehicle.

Another object of the invention is to provide a motor driven vehicle of the type above set forth, the same having endless treads at each side thereof, which treads converge toward their upper runs, theground engaging surfaces of said treads being constructed and arranged to be substantially horizontal when in ground engaging position.

It is also an object or this invention to provide a motor driven vehicle of the type above mentioned having endless tracks at eachside thereof together with pneumatic means pushing downward on each track respectively to relatively move said frame and track to tilt said vehicle to maintain the same substantially upright.

It is also an object of this invention to provide a motor driven vehicle of the type above mentioned having a frame, pairs of wheels at its front and rear ends respectively, endless tracks running over said wheels at each side of said frame, a central endless track disposed between said tracks and normally disposed out of engagement with the ground and means for yieldingly supporting said last mentioned track.

It is also an object of the invention to provide a motor driven vehicle of the type above mentioned having a frame adapted to be straddled by an operator occupying a seat on said frame, said vehicle having means for controlling the' same by' the hands or feet of the operator.

These and other objects and advantages of. the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughoutthe several views and in which Fig. l is a view in side elevation of the device;

Fig. 2 is a plan view of the device;

Fig. 3 is a view of a portion of the tread or track used;

Fig. 4 is a view in side elevation of a portion of said track;

Fig. 5 is a view in end elevation of a portion of said track also showing part of the supporting wheel;

- Fig.- 6 is a vertical section taken substantially on line 66 of Fig. 2 as indicated by the arrows; Fig. 7 is a vertical section taken substantially on line 1--l of Fig. 2 as indicated by the arrows; Fig. 8 is a vertical section taken on line 88 of Fig. 2 as indicated by the arrows;

Fig. 9 is a vertical section taken on line 99 of Fig. 2 as indicated by the arrows;

Fig. 10 is a somewhat diagrammatic plan view showing certain controls;

Fig. 11 is a vertical section through certain air control valves used; and

Fig. 12 is a vertical section through a modified form of supporting and tilting means.

Referring to the drawings, a motor propelled vehicle is shown comprising a frame designated generallyas 20. Said frame comprises end caste ings 20a and 20b between which extend laterally spaced bars 20c. Castings 20a have longitudinally extending portions 20d through which extend headed and nutted bolts 2lextending through slots 20a in bars 200 so that said frame may be adjusted and lengthened or shortened. Each bar 200 has a laterally projecting lug 20! through which extends a headed limiting or stop screw 22 engaging casting 200. at its outer end. A look nut 22a is disposed on screw 22 and engages the outer side of lug 20). Each of the castin s 20a and 2% has formed therein a pair of cylinders 20 and 2071. respectively. These cylinders are spaced laterally and disposed equal distances at each side of the center of the machine. Plungers or pistons 23 and 24 are disposed respectively in cylinders 20g and 20h, the same preferably being provided with piston rings 24am, two of which are shown. As shown in Fig. 8, screws 21 extend through the sides of cylinders 20g and 2071. into grooves 240 in pistons 24 andsimila'r grooves in pistons 23 so that the outer or downward movement of said pistons are limited thereby.

*Each of the plungers has a downwardly projecting extension 23a and 24a respectively which is of greater diameter than the plunger, the same forming a shoulder engaging the lower end of the adjacent cylinder 209 or 2th. Compression coiled springs 29 are disposed between the tops of plungers 23 and 24 and their respective cylinders 209 or 29h. Extensions 23a have secured thereto spindles 23b respectively and while these might be variously formed, in the embodiment of theinvention illustrated they are shown as integral with extensions 23a. Wheels 25 are journaled on the spindles 23b, it being understood that there are four of said spindles, two at each end of frame 20. As shown in Figs. 8 and 9, the axes of cylinders 20!] and 2012. converge toward their upper ends. Spindles 23b thus are inclined outwardly and upwardly and wheels converge toward their upper ends.

Wheels 25 are provided with pneumatic tires 26 of any suitable or standard type. Running over the wheels 25 at each side of the frame are endless tracks 28. These tracks are composed of connected units 28a shown in Figs. 4 and 5 as of rectangular form in plan and being connected adjacent their ends by the hinges 28c. Alternate units 28a have the tire engaging members 30 shown as formed of rods having end portions extending perpendicular to the inner sides of units 28a and having intermediate portions formed on the arc of a circle somewhat larger than the outer circumference of the section of tire 26. While units 28a may be variously made in the embodiment of the invention illustrated they are shown as in the form of I beams (see Fig. 4), each having secured thereto a curved plate 3! which extends across the space between the units and fits against a curved surface on the fiange of the adjacent unit. Units 28a are shown as of general V-shape in end elevation so that the lower surfaces 28b thereof are substantially horizontal in the lower run of tracks 28 as shown in Figs. 5, 8 and 9. The lower ends of projections 23a are formed as forks 23d and bars 34 fit between the sides of and fit longitudinally of said forks. Bearing rollers 35 carried on small shafts or pins 36 extending through the sides of forks 23d engage the top and bottom surfaces of said bars 34. Bars 34 are of slightly angular shape longitudinally and at their adjacent ends are pivotally connected to a projection 31a of a piston or plunger 31 disposed in a cylinder 380. formed in a member 38. Member 38 is secured by bolts 39 to the central portion of a bar 201 extending parallel to bar 200. Bar 202' is connected at its ends to members 207' and 20k: bored at their upper ends to receive the outer ends of spindles 23b, said spindles being provided with nuts 40 at the outer sides of bars 202'. Members 287' have projections 20m extending parallel to projections 20d and having slots receiving the ends of bars 202'. Headed and nutted bolts 4! extend through projections 20m and through slots 201i in bars 202' so that members 237' and bars 202' may be adjusted laterally and held in fixed relation. Bars 2lli also have laterally projecting lugs at their ends through which extend headed stop screws 42, the outer ends of which engage members 2M, said screws being provided with lock nuts 43. The members 207' and 207s are also formed as forks at their lower ends and receive the ends of bars 34 which extend parallel to the bars 34 already described which are disposed in forks 23d. Members 20k also have the rollers 35 secured therein engaging the tops and bottoms of bars 34. It will thus be seen as clearly shown in Fig. 8 that there are pairs .of bars 34 at each side of the machine. Shafts are secured in and extend between these pairs of bars 34 and form the spindles for wheels 41, said wheels preferably being provided with pneumatic tires 48 and being disposed centrally of the tracks or treads 28. Projection 37a is in the form of a fork as shown in Fig. 9 and the lower ends of this fork are bifurcated to receive therein the adjacent ends of bars 34, said bars being pivoted to projections 31a by the pivot bolts 5|. A shaft 53 extends through and between the sides of fork 31a and has journaled thereon another wheel 41' similar to the ones already described and which also bears on the center of the tracks or treads 28. It will be understood that there are two pairs of the bars 20i, the outer bar 20i extends between bars 207' and 20k and the inner bar 202' extends between members 23a. This is seen in Fig. 9.

Supported upon members 200 of the frame is a motor 55. While this could be of any desired form it preferably and in practice has been a motor of the internal combustion type and is illustrated in Figs. 2 and 6 as having opposed cylinders 56a in which are disposed pistons 55b connected by the connecting rods 560 to a crank shaft 56d. Crank shaft 56d is provided at one side of the motor with a sprocket 51 over which runs a chain 58 also running over a sprocket 59 secured to a shaft 60 extending into a gear shift box 6| carried on the frame. The gear box 6l will be of the usual construction provided for automotive vehicles'and will have gears providing for two or three forward speeds as desired. The transmission shaft 62 extending from the gear box 6| is provided with sprockets 63 and chains 64 run over these sprockets respectively and over sprocket 65 secured to the inner sides of wheels 25 by bolts 68, chains 54 thus driving treads 28. A main clutch such as commonly used in automobiles connects shaft 60 to a transmission shaft in gear box 6|.

A compressed air tank 10 will be carried on the vehicle preferably at the rear of the frame and will be supplied with compressed air through a conduit H which will extend to an air compressor not shown which will also be carried on the frame and driven from motor 56. A supply pipe or conduit I2 leads from tank 10 and this will extend to a pipe 13 connected to one end of the air control valves 14. Each valve 14 has an inlet portion 14b and a delivery portion "a. The delivery portion 14a. is connectedto the cylinders 20g and 2012. at each side of the machine as shown in Fig. 10, conduits I and I6 extending respectively from the delivery sides of valves 14 to the said cylinders at each side of the machine as shown in Fig. 10. Chamber Ma of valve I4 has a port communicating with the atmosphere and closed by valve 140 carried on a rod 1412 and extending through a portion of valve 14 and.

through a suitable packing gland Me. A compression coiled spring I4 1 acts to unseat valve 14c. Rod 14d is pivotally connected to one end of a cross bar or cross head Mg. Valve chamber Mb has a port communicating with chamber Ma which is closed by a valve 14h carried on a rod m extending through a portion of valve I4 and packing gland Me. A compression coiled spring n1 acts to hold valve 'IIh normally closed. Rod Iuz' is pivotally connected to the other end of bar Mg. Bar Hg is pivotally connected at its central portion to a rod 11 in turn connected to the core I8 of an electro-magnet or solenoid I9. A conductor 80 is shown extending between the solenoids l9 and conductor 8! extends from one solenoid to spaced contacts 82 arranged circumferentially on a member 83 carried on an oscillating head 84 which is in turn mounted on a, vertical shaft 85 secured in a bearing 86 (see Fig. 2). Bearing '86 is secured by bolts 81 to the front casting r'nember b. Another conductor 98 extends from the other solenoid 19, being connected to the winding thereof to spaced contacts 9| also carried on member 83. Contact members 82 and SI will be insulated from the frame. A member 92 is provided having an elongated sleeve rotatof the frame toward the other side of the machine. The connection between the end castings and the wheels on one side is in effect elongated and this causes the machine to rock about its sup- P rt on the track at the other side or to be tilted. The purpose of this tilting is to maintain the balance of the machine when going over uneven ground or ground that is lower at one tread than the other. The machine is thus kept in upright position.

Carried on the frame and preferably disposed as shown on top of the gear box 6| are a pair of cylinders I00 and IOI. Each cylinder contains a piston I02 which will preferably be provided with piston rings I03. The connecting rod I04 connects each piston respectively to links I05 which are in turn respectively connected to crank arms I06. Crank arms I06 are connected to shafts I01 extending into the gear box 0|. The oscillation of crank arm I06 and shaft I01 will release a clutch connecting sprocket 63 to its drive shaft and will also apply a brake to said sprocket. This type of clutch and brake operated by a, cam (115K and crank is now well known in the art and is commonly used on certain automotive vehicles such as tractors or trucks. The details of such clutch and brake are not shown and it is thought need not further be described. The cylinders IOI and I02 are controlled by valves I09 and H0 able on a shaft 93 secured to member 84. Member 92 has a flange 92a, movable adjacent member 82 and having thereon a contact member or lug 92b. Member 92 is provided with a handle 920 by which it may be insulated about the axis of shaft 93. Member 92 will be electrically connected to the frame of the machine or to theground. With the described construction it will be seen that when contact point 92b is brought into engagement with one of the contacts 82 that said contact and thus conductor 8I will be connected to the ground. This will close a circuit through the respective solenoid 19 which may be v traced from ground 98 through conductor 95 to' one side of battery 94, thence through conductor 89, conductor 80, the winding of solenoid 19, conductor 8|, contact 82 and member 92 to ground. This will operate or energize the said solenoid I9 causing its core member I8 to move quickly th;rein. When member 92 is oscillated to bring its contact point 92b into engagement with one of the contact members 9 I, the other solenoid will likewise be energized. The circuit for this may be traced from ground 98 through conductor 95, battery 94, conductor 89, conductor 80 through the winding of the solenoid, conductor 90, contact 9| and member 92 to ground. Thus by oscillating the handle 92c the operator can energize either solenoid 18 at will. When core member 18 moved into its solenoid 19 rods 14a. and Mi are moved toward the solenoid. This quickly closes valve 14c and then opens valve 14h. Air can now pass from pipe 18 to pipe 15 or pipe' 16 into the cylinders 24g and 24h at one side of the machine depending upon which solenoid is energized. When air is-admitted to these cylinders the plunger 23a. and 23b are depressed or forced downwardly and this causes a rocking or tilting connected thereto respectively by pipes III] and II I. The cylinders 38a already described aresupplied with air through pipes II2 shown in Fig. 10 as connected to the control valve II4 by a pipe II3. Pipe 'I2 is shown as supplying air to the valves I09, H0 and H4. As stated the member 84 is oscillatable about the vertical axis of shaft 85. A handle bar H6 is secured to the side of member 84-.opposite that to which members 92 and 93 are connected and member H6 is provided with a grip handle I Ilia. Grip handle IlIic will be rotated and connected by the usual flexible shaft to the throttle of motor 56. Handle I I60, thus forms an accelerator member for motor 58. Handles 92c and H60. are symmetrical in relation to the central line of the machine or the axis of shaft 85 and thus constitute handle bars in form something like those of the common bicycle or motorcycle. The valve members I09, I I0 and H4 are similar to the valve members I4 already described and have their valve rods connected to bars II8, II9 and I20 respectively. Bar II8 has connected thereto a flexible member such as a wire or cable I2I and this is connected to member 84 at some distance from its pivot. A tensile coiled spring I22 is preferably disposed in cable I2I. A cable I23 is connected centrally to bar II9 and this is connected to member 84 at the side of shaft, 85 opposite to' that to which cable I2I is connected. Atensile coiled spring I24 is preferably placed in cable I23. Another cable I28 is connected centrally to bar I20 and extends to member and is connected thereto at the same point to which cable I2I is connected, a tensile coiled spring I21 being insertedin cable I26. Another cable I28 is connected to cabl I26 some distance from bar I20 and extends to and is connected to 'memb er 84 at substantially the same point to which cable I23 is connected. A tensile coiled spring I29 is inserted in cable I28. 1

With the structure described it will be seenthat if member 84 is oscillated in a clockwise direction cables I2I and I28 will be pulled upon and bars H8 and I20 will be moved outward. Cables I23 and I28 will be slacked so that no tension will be exerted by these cables. The bars H8, H9 and I are similar to bar 14g. When bars I I8 and I20 are thus drawn outward air will be supplied to cylinder HM and cylinders 38a. The pistons in these cylinders will thus be pushed outwardly. The crank arm I06 connected to the rod I04 of cylinder IOI will be oscillated and the drive to the wheel on one side of the machine will be released or unclutched and a brake will be placed on the drive on said side. At the same time plungers 31. will be forced downwardly and the rollers 41 will be pushed downwardly against the tracks 28. When rollers 41 are thus pushed downwardly the effect is to raise the end portions of the tracks or to lessen the friction on the ground at the end portions. This is indicated in the dotted lines in Fig. 7. In practice a very decided effect is obtained. The wheels and track at one side of the machine are still being driven while the track at the other side is not being driven and is being retarded. The driven track then causes the machine to turn toward the undriven track. The turning is greatly facilitated by the downward motion of the wheels 41.. The tracks are really supported only at the central portion thereof and turn with very little ground engagement. The machine thus quickly responds and a very short turn can be made. In fact the gear box 6 I. The sprocket I48 acts as a resilient tightening means for the chain I42. A spring I50 surrounds shaft I32 and is disposed in the bore 201), the same engaging at its upper end with the top of said bore and engaging the top of member I at its lower end. Members I35 machine almost turns about a central vertical axis of one tread.

If the member 84 is oscillated in a counter clockwise direction cables I2I and I26 will be slacked but tension will be placed on cables I23 pushed outwardly with the desired force and the turning or tilting of the machine is practically instantaneous.

The castings 20a and 2022 are each provided centrally thereof with a bore 20p opening at the lower side thereof. A shaft I32 extends centrally through bore 201) and through said casting, the same projecting somewhat above the top of said casing and having a pin I33 therethrough adapted to engage a washer I34 on the top of the casting. Shaft I32 passes through washer I34. Shaft 832 is secured at its lower end to a fork member I35. Member I35 has a fork portion below each bore 201) and these are connected by elongated bars I35a extending between the sides of the fork. Shafts I31 are secured in and extend between bars I35a and have journaled thereon rollers I38. Suitable bearings will be provided for the rollers or wheels I38. An endless track I of any suitable or standard form extends around the rollers or wheels I38 as shown in Fig. 6. One shaft I31 preferably the end one, is provided with a sprocket I4I over which runs a chain I42 also running over a sprocket I43 secured to a shaft I44 projecting from the gear box GI. A lever arm I46 is pivotally connected at one end to a small bracket I41 secured to one of the bars 202', which arm has mounted on its other end an idler sprocket I48 engaging the top run of chain I42. Lever arm I46 is engaged at its top side by compression coiled spring I49 also engaging the small flanged bracket I50 secured to the side of are thus resiliently supported on springs I50 when tread I40 is in contact with the ground. Member I 35 has rods I35b secured thereto and projecting upward therefrom which fit in and slide respectively in bores 20: in castings 20a and 20b. Rods I35b act as guide rods for members I35.

The frame, upper run of the tracks 28 and the major portion of wheels 25 are enclosed in 2. casing I55 as shown in Figs. 1 and 8. A bracket I56 of general U-shape is secured-to the underside of easing I55 beneath an opening therein and an.

operators seat I51 is secured to bracket I56 by a resilient bracket I58. Control levers I59 and I60 are shown as projecting through casing I55 in convenient position for manipulation of the operator occupying seat I51. One of thelevers I53 will be a shift lever for giving the desired speed to the wheels 25 and treads 28, the other lever I60 may control the gear shift for putting into or out of operation shaft I44 and sprocket I43 which drive the tread I 40 and for shifting gears for tread I40 to drive it at the desired speed. Tread I40 preferably should travel at the same linear speed as tracks 28. v

Oscillating pedals I6I are provided at each side of the machine and are disposed at the outer side of easing I55. These are connected to shafts I82 and said shafts will have arms 32:1 and I62b thereon respectively to which will be connected cables. The arms I62a will be connected to cables I23 and I28 respectively, while the other arms I62b will be connected to cables IN and I25 respectively. The operation of one pedal IBI will therefore, be the same as swinging member 84 in one direction by the handle bars and the operation of the other pedal will be the same as swinging member 84 in the other direction by the handle bars. The operator can thus control the steering by foot pedals ISI and can remove his hands from the handle bars. He may wish to do this to use his hands to operate a gun.

Another pair of oscillating pedals I8. are provided at each side of the machine and at the outer side of casing I55 secured to shafts I83. One of these shafts I83, preferably the one at the right hand side of the machine, will have connected thereto through arm I84 cables I85 which will run over suitable pulleys (not shown) and be connected to the members 8 and H9 so as to operate them simultaneously. This will operate valves I09 and H0, releasing the clutches in the transmission box or gear box 5| and applying the brakes therein to both driving shafts for the treads. Both treads will therefore be retarded 01' braked and the machine will be quickly stopped. It will be noted that this is done without operating valve II4 to depress the treads. The pedal II at the left will be actuated to operate or release the main clutch on shaft 60 so that this shaft and sprocket 59 are disconnected from the motor to permit shifting of gears by the gear shift lever I59. This is the usual arrangement in an automobile of releasing the clutch to shift the gears. Foot rests I63 are pro- Ill.

or made integral therewitha member "II and the fork or' lower wheel-carryin Portion 23 will have its upper end formed as a shaft. or spindle Member I has a flange I1IIa secured by screws I12 to the mating flange I13a of a member I13, a flexible diaphragm I14 being disposed between flanges lllla and I13a and secured by bolts I12. Member I13 has a cylindrical portion at its upper end bored to receive and guide the upper end of spindle "I, which spindle also passesthrough a bore in the lower end of member I10. Spindle IN is provided with a collar I15 and the central part of the diaphragm I1. is held between collar I15 and another collar I16 secured on spindle I1I. spring I11 surrounds spindle I1I above collar I18 and engages a shoulder at the upper end of the chamber in member I13. An air supply pipe I18 communicates with the chamber in member I13 above diaphragm I14. Some resilient means such as the block I80 made of rubber or similar material will be disposed in the bore in the upper end of member I13. A vent. opening I10b extends into the chamber in member I10 below diaphragm I14. v

With the described construction the frame will be supported on spring I11 which will transmit the load thereof through spindle I1I to the wheels 25 and tracks 28. When it is desired to tilt the frame or exert pressure downwardly on spindle I1I air will be admitted to the chamber in member I13 just as it is admitted to the cylinders 20g and 20h. Diaphragm I16 will be depressed as will spindle IN. This will react to tilt the frame 20 laterally. Should spindle IN A compression coiled move to the upper end of the bore in member I13 it would be cushioned by block I80.

From the above description it will be seen that I have provided a highly novel and useful motor driven vehicle. The vehicle is designed to run on rough ground and on ground where there are no well made trails or roads. The wheels 25 and treads 28 will be driven at the desired speeds. Ordinarily only the treads 28 will be used to drive the vehicle. If soft ground should be encountered so that the treads 28 sink into the ground sufficiently the track or tread I will engage the ground. This may then be driven at the desired speed through sprocket I43 and the chain I42 and this tread will assist in the propulsion of the vehicle. While the vehicle will have many uses, it will obviously be of great beneflt and have a great utility as a military vehicle. It could be used for quick transportation across country and it could also be used as a type of one man tank. Tandem seats could be used if desired, one being for an operator and the other for a gunner. The casing I55 could be used as an armor plate. A gun could easily be mounted. on the forward part of the vehicle to be manipulated by the operator. The type of tread used running on pneumatic tires is very feasible. The wheels 25and treads 28 were given the upwardly converging position to provide ease in steering. It is much easier to steer the vehicle with the treads and wheels so arranged. As above described, the machine can be steered either from the handle bars having handles 92c and Ba or it can be steered from pedals I6 I. It can also be quickly stopped by operating one of the pedals I8I. The device is thus under the complete controlof the operator and it can be driven at fairly high speeds across very rough country. The device has been amply demonstrated in actual practice and found to be very successful.

rangement and proportions of the parts, without departing from the scope of applicants in-.

vention, which generally stated, consists in a device capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

1. A motor propelled vehicle having in combination, a. longitudinally rigid frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of wheelsrotatably mounted in the front and rear of saidframe respectively, endless tracks running over said front and rear wheels one at each side of said frame, a seat on said frame between said pairs of wheels so arranged that the operator occupying the same straddles said frame and upper runs of said tracks, means for driving one of said pairs of wheels from said motor and steering controls in front of said seat adapted to be grasped by the operator operatively connected to said tracks respectively for steering said vehicle.

2. A motor propelled vehicle'having in combination. a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of laterally spaced wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels one at each side of saidframe, a seat on said frame between said pairs of wheels so arranged that the operator straddles said frame and the upper runs of said tracks, foot rests at each side of said frame forwardly of said seat arranged to be engaged by the respective feet of the operator, means for driving one of said pairs of wheels from said motor and steering controls in front of said seat adapted to be grasped by the operator for acting on said tracks for steering said vehicle.

3. A motor propelled vehicle having in combination. a frame constructed and arranged to be straddled by the operator, 8. motor on said frame, pairs of laterally spaced wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels one at each side of said frame, a seat on said frame between said pairs of. wheels so arranged that the operator straddles said frame in the upper runs of said track, brake levers at each side of said frame forwardly of said seat adapted to be engaged by the feet of the operator respectively, means for driving one of said pairs of wheels from said motor and steering controls in front of said seat adapted to be grasped by the operator acting wheels and above said casing. said casing being constructed and arranged to be straddled by the operator occupying said seat, members at each side of said casing adapted to be engaged by the feet of the operator respectively and steering controls in front of said seat adapted to be grasped by the operator and acting on said tracks for steering said vehicle.

5. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels one at each side of said frame, said wheels of each pair being inclined upwardly and inwardly toward said frame, means for driving one of said pairs of wheels from said motor and means for steering said vehicle.

6. The structure set forth in claim 5, said treads having ground engaging surfaces which are horizontal in the lower runs of said treads.

7. A motor propelled vehicle having in combinaticn, a frame constructed and arranged to be straddled by the operator, a motor on said frame,

pairs of wheels at the front and rear of said framerespectively, endless tracks running over said front and rear wheels one at each side of said.

frame, the upper runs of which are in such proximity as to be straddled by the operator, means for driving one of said pairs of wheels from said motor for progressing said tracks and vehicle and means for tilting said frame laterally in either direction at the will of the operator for maintaining the balance of said vehicle and keeping it in upright position.

8. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of laterally spaced wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels one at each side of said frame, the upper runs of said tracks being in such proximity as to be straddled by the operator, means for driving one of said pairs of wheels from said motor and progressing said tracks and means for pressing down on said tread at either side of said frame for relatively moving said frame and tilting the same.

9. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels, one at each side of said frame, a seat above said tracks mounted on said frame for said driver, the upper runs of said tracks being arranged to be straddled by the driver occupying said seat, means for driving one of said pairs of wheels from said motor for progressing said tracks and means for braking the wheels at one side of said frame to facilitate turn ing of said vehicle.

10. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels, one at each side of said frame, means for driving one of said pairs of wheels from-said motor for progressing said tracks and an endless track disposed between said tracks with the bottom of its lower run being disposed some distance above the bottom of the lower runs of said first mentioned tracks. ll. The structure set forth in claim 10 and means for yieldingly supporting said last mentioned tread at the end portions thereof. K 12. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels, one at each side of said frame, means for driving one of said pairs of wheels from said motor for progressing said tracks, an endless track disposed between said tracks with the bottom of its lower run being disposed some distance above the bottom of the lower runs of said first mentioned treads and means for driving said last mentioned track from said motor. 13. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of laterally spaced wheels at the rear and front of said frame respectively, endless tracks running over said front and rear wheels, one at each side of said frame, means for yieldingly supporting said frame at each end from said tracks and fluid actuated means disposed at the ends of said frame for causing relative movement between said wheels at one side of said vehicle and said frame.

14. The structure set forth in claim 13 and a control member in front of the operator adapted to be manipulated by the operator for actuating said last mentioned means.

15. A motor propelled vehicle having in combination, a frame, a motor on said frame, pairs of wheels at the front and rear of said frame respectively, endless tracks running over said front and rear wheels, one at each side of said frame, cylinders at each side of said frame at the front and rear thereof, plungers in said cylinders connected to said wheels and tracks and fluid actuated means for depressing said plungers at either side of said frame for tilting said frame in either direction to balance said vehicle and maintain it in vertical position.

16. The structure set forth in claim 15 and a control member in front of the operator adapted to be manipulated by the operator for actuating said last mentioned means.

1'7. A motor propelled vehicle having in combination, a frame, said frame having a pair of cylinders therein at its front and rear ends, pistons in said cylinders, axles carried by said pistons at one side thereof, wheels journalled on said axles, means for directing fluid into said cylinders at one side of said frame to cause said frame to rock about the wheels at the other side of said vehicle the pistons in the cylinders at the other side of said frame being maintained in normal position.

18. The structure set forth in claim 1'7, the axes of said cylinders extending downwardly and outwardly at each side of said frame.

19. A motor propelled vehicle having in combination, a frame, said frame having a pair of cylinders therein at its front and rear ends respectively, pistons in said cylinders having extensions therein, axles carried by said extensions, wheels journalled on said axles, endless tracks extending over the wheels at each side of said frame respectively and means for supplying fluid to said cylinders at one side of said frame to move said pistons in said cylinders'to cause relative movement between said frame and axles at one side of said frame while maintaining said pistons at the other side of said frame stationary to rock said frame about the wheels at said other side.

20. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a motor on said frame, pairs of laterally spaced wheels at the front and rear of said frame respectively. endless tracks running over said front and rear wheels at each side of said frame, the upper runs of which are in such proximity as to be straddled by the operator, means for driving one of said pairs of wheels from said motor for progressing said tracks and vehicle and means for lengthening the distance between said wheels and frame at one side of said frame to rock said frame.

21. A motor propelled vehicle having in combination, a frame constructed and arranged to be straddled by the operator, a pair of laterally spaced wheels at the front and rear of said vehicle, axles on which said wheels are journalled,

endless tracks extending around the wheels at 10 

